Central European belt of magnetic anomalies

The Central European Belt of Magnetic Anomalies is a geomagnetic phenomenon that was first discovered in the form of the Berchtesgaden Anomaly . This represents a strong disturbance in the earth's magnetic field , which indicates the existence of rocks of high magnetic susceptibility under the Northern Limestone Alps .

The Berchtesgaden anomaly was discovered in 1954 in the course of the dissertation of the Munich geophysicist R. Gaenger and examined more closely by geoscientists from Baden and Vienna from 1976 to 1995. Similar anomalies were later discovered in the upper Engadine , in some places in the northern Alpine foothills and finally in southern Poland near Krakow . The anomalies appear as a superposition of magnetic disturbance bodies , which have flat field gradients but high disturbance amplitudes.

During the aeromagnetic flight of the Vienna Basin , strong disturbances in the magnetic field came to light, reaching a few hundred nT ( nanotesla ). Despite a similar pattern of anomalies over the 700 km long route, no uniform interpretation has been achieved, although the cause is suspected to be in the old basement mountains of the Alps and the Bohemian Massif. In Moravia it could be highly magnetic rocks in the pre-Paleozoic basement, but in the west no such structures are known at such depth. Recent research shows similar disturbances in the Tauern window and in the Semmering window , where they could originate from the deep Lower Eastern Alps . In the Vienna Basin, they conceal the tectonic connection between the Eastern Alps and the Western Carpathians, which was previously considered to have been confirmed by classical methods.

literature

• Federal Geological Institute, Vienna Basin and adjacent areas . Geological thematic maps 1: 200,000 and explanations, Vienna 1993
• Wolfgang Seiberl, Aeromagnetic Map of the Republic of Austria 1: 1,000,000 , GBA / Univ. Vienna 1991